initial commit. config parsing

.gitignore

+/target
+config.toml
\ No newline at end of file

Cargo.lock

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Cargo.toml

+[package]
+name = "balloon_tx_monolith"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+anyhow = "1.0.70"
+serde = { version = "1.0.160", features = ["derive"] }
+toml = "0.7.3"

config.toml.example

+# where to load images from
+# each path should be a different camera,
+# so that we get an even blend of images
+# want one path to be used more often?
+# just add it twice to the config!
+paths = [
+      "img1",
+      "img2",
+]
\ No newline at end of file

src/config.rs

+use std::{fs, path::PathBuf};
+
+use anyhow::{anyhow, bail, Context};
+use serde::Deserialize;
+
+#[derive(Deserialize, Clone)]
+pub struct Config {
+    pub paths: Vec<PathBuf>,
+}
+
+impl Config {
+    pub fn load() -> anyhow::Result<Self> {
+        let file_contents = read_conf_file()?;
+        let config = toml::from_str(&file_contents).context("parsing config file")?;
+
+        Ok(config)
+    }
+}
+
+fn read_conf_file() -> anyhow::Result<String> {
+    let filenames = ["config.toml", "/etc/balloon_tx/config.toml"];
+    for filename in filenames.iter() {
+        if let Ok(x) = fs::read_to_string(filename) {
+            return Ok(x);
+        }
+    }
+
+    bail!("Could not open config file. Should either be `config.toml` in the current directory, or in /etc/balloon_tx/")
+}

src/main.rs

+use config::Config;
+
+mod config;
+
+fn main() -> anyhow::Result<()> {
+    let config = Config::load()?;
+
+    Ok(())
+}